Document scanners are well-known in the art. Prior art approaches, however, especially for large documents, tend to have complex designs to try to achieve document flatness along the scan line. Multiple camera systems are generally difficult to align and to keep in alignment; and systems tend to be sensitive to vibration and other external forces. Finally, systems tend to have a limited dynamic range, owing to the varying and limited physical characteristics of individual cells in charge-coupled devices (CCDs) commonly used as photo-electrical transducers in such systems, and to the difficulty in achieving uniform illumination along the scan line.